Orbital rotary machines are known, for example as described in my earlier Australian Patent No. 474,336 and in Australian Patent Application No. 19025/76. These machines have known definite advantages, such as a very low sealing blade speed, due to the fact that for each revolution of the crank shaft, that each blade merely oscillates across the surface of the interior of the orbital chamber or housing for a distance equal to twice the throw of the crank. Hence instead of for each revolution the blade travelling a distance of the circumference of the interior of the casing or housing, the blade only travels the distance of twice the crank throw.
It will be realised that the chambers between each blade in the rotor must be sealed, so that there is no transfer of fluid between the chambers, or loss of pressure from a working chamber.